A new way of making prostheses

A new method of making artificial limbs at SGH’s Prosthetics and Orthotics clinic ensures prompt rehab for amputee patients.

For patients who have had a lower limb amputated, using a well-fitting prosthesis as soon as possible helps them start rehabilitation faster.

At Singapore General Hospital ’s (SGH) Prosthesis and Orthotics (P&O) clinic and workshop, patients can get fitted with an artificial device on the same day under a new method of fabricating and fitting artificial limbs. Thus, rehabilitation and mobility are not delayed.

The Direct Socket Below the Knee Amputation method takes just a couple of hours to cast, fabricate, assemble and fit a prosthesis on to a patient. “This is very convenient for the patient, who can get the prosthesis on the same day.

If no adjustments to the device are needed, the patient can start working with a physiotherapist on walking and other mobility skills,” said Mr Saros Rouen, Principal Prosthetist and Orthotist (Management), Podiatry Department, SGH.

SGH is the first in Southeast Asia to introduce this method of fabricating a prosthesis for below-knee amputations. This is no small feat considering that the hospital only started its own workshop in early 2023. Before, manufacturing and assembly of prostheses for its patients was supported byTan Tock Seng Hospital (TTSH). With its own P&O workshop, SGH is now able to better support patients through a full range of services, including the manufacturing of both prostheses and orthoses, said Mr Rouen.

Prostheses are custom-made devices that fit over missing limbs, while orthoses help support patients with muscle weakness or joint instabilities through the use of knee ankle foot orthoses, ankle foot orthoses, and insoles and modified shoes for common ailments like flat feet. “We aim to be a forerunner in cutting-edge prosthetics fitting and fabrication technology for better patient care, such as in assistive robotics and 3-D printing,” said Mr Rouen.

With the introduction of its Direct Socket Below the Knee Amputations method, the service has substantially reduced the time taken to receive prostheses. Under the traditional method, which involves the full process from casting to fitting, it takes as long as a month before a patient is able to start walking with a prosthesis.

The P&O clinic works in tandem with pre-operative rehabilitation medicine specialists, physiotherapists, prosthetists and orthotists, and social workers to provide a holistic care path for patients. Besides providing prosthetic and orthotic services to patients in SGH, it also supports patients in other SingHealth hospitals — Sengkang General and Changi General Hospitals.

Amputations can be due to accidents or complications from diseases or infections. Mr Saros reckoned that nine in ten of the SGH patients that he fits for prostheses are for diabetes-related complications. “We pride ourselves on providing fast access to postamputation care to allow patients to start rehabilitation quicker and provide a good quality of life after surgery,” he added.

Making a direct below-knee amputation socket

Prostheses made using the Direct Socket Below the Knee Amputation method are lighter, stronger, more comfortable, and easier to use than those made traditionally. Moreover, patients are able to get their prostheses within a few hours instead of as long as a month.

This is because the fabrication of the prosthesis or socket under the new method is done directly on the patient using glass fibre, resin and a hardener, said Mr Saros Roeun, Principal Prosthetist and Orthotist, SGH. “The glass fibre and resin are bound together during the process, giving a strong and durable prosthesis with an increased range of motion and a snug socket fit.”

In making a socket to fit over a patient’s stump, Mr Rouen first makes an assessment to check the patient’s muscle power, joint function, and sensitive areas on the stump. Making of the socket mould (above, from left) involves adding layers of materials — a casting liner first, then an insulator, glass fibre, then another insulator — before the resin, that includes a hardening agent, is injected into it. The mould is then left to harden for about 10 minutes. The moulded socket, removed from the leg, is ready for cutting and smoothing. The prosthesis is ready to be fitted and worn within 90 minutes, compared to the traditional method where, after casting, the component is ordered for delivery a couple of weeks later.

The much shorter turnaround time allows more patients to be seen. More importantly, patients can move on to rehabilitation more quickly, said Mr Roeun. The workshop does not take up much space as large or complex machines, such as those required for the traditional manufacturing of prostheses, are not needed.

This article was first published in Singapore Health Jul-Aug 2024 issue.